Strap for a full respirator mask

ABSTRACT

A strap for respirator masks comprises a head strap piece, made from elastically flexible synthetic material, with a strap fixing piece and a head plate with a greater wall thickness than the attached head straps. A neck strap, connected to the mask at two fixing points and an extending temple strap, which may be introduced in a detachable and length adjustable manner into fixing clips attached to the head straps, are fixing to the strap fixing piece. The head strap piece thus consists of a straight and a curved piece. The crown-shaped embodiment with the elastic temple band is associated with good fitting and wearing properties and low maintenance requirements.

This invention relates to a strap for respirator masks consisting of ahead strap piece with two head straps connected to the mask at twofixing points and a joint strap fixing piece for length adjustable neckstraps held at two other mask fixing points.

Such a strap made of a flexible but longitudinally non-stretchingplastic material comprising a four-point fastening to the mask at thestrap ends is known, for example, from JP 2000-102624. This straparrangement with only four fixing points can easily be mounted to themask, which also makes it easy to clean. However this design has adisadvantage as it does not ensure a firm fit of the mask, especiallywhen its wearer is put under high strain that causes increased sweatproduction or when additional forces act on the mask from additionalequipment mounted to it such as a welder's attachment or the like. WhileJP 2000-102624 does propose side straps integrally molded to thefastening plate, which means consisting of the same material as thefixing plate, in conjunction with a five- or six-point fastening, thiscomplex strap design with regard to strap adjustment and fastening isnot adequate to ensure safe positioning of the respirator mask on awearer's head. A five- or six-point strap arrangement would also requirea greater mounting and adjusting effort and make cleaning the mask moredifficult. Another disadvantage of the strap known from JP 2000-102624is instability of the flexible strap, which makes putting the mask ondifficult and time-consuming for wearers who are out of practice.

It is therefore the problem of this invention to provide a strap forrespirator masks that is easy to handle and take care of and thatensures a safe fit when the wearer is exposed to physical strain or whenthe weight of the mask is increased.

This problem is solved according to the invention by a strap attached atfour fixing points comprising the characteristics described in claim 1.

In other words, the concept of the invention is that the head strappiece made of a synthetic material comprises a flexurally stiff headplate between the strap fixing piece and the head straps, compared towhich the head straps are considerably more flexible. In this way, thehead strap piece is curved in the head strap sections and straight inthe head plate section so that it can be put on fast and easily;together with the strap fixing piece and an extending temple strapattached to the fixing clips of the head straps it takes the shape of ahat with curved head straps and a straight head plate so that it can beopened like a cap and placed on the head without prior arranging andaligning the strap and without any risk that the strap might gettwisted.

The head strap piece is made of an easy-slide synthetic material andcauses minimal friction when slid over head hair. However, the mask issafely and tightly kept on the wearer's head even when the wearer isexposed to strain and produces the respective amounts of sweat.

The subordinate claims disclose further characteristics and advantageousimprovements of the invention.

Another advantage of attaching the temple strap to fixing clips that aredirectly connected with the head straps is that this six-straparrangement only requires a four-point fastening to the mask, that is,two fixing points for the head strap piece and the temple strap and twofixing points for the neck strap. This makes assembly and disassemblyfor cleaning the respirator mask easier.

In an embodiment of the invention, the temple strap and the neck strapare conducted in guiding slots of the strap fixing piece so that thesmooth and non-elastic neck strap covers the poorly sliding temple strapsection facing the wearer's head in the strap fixing piece, thus makingthe strap slide easily over the head hair without tearing on it orpinching it when the mask is put on. Holding the neck and temple strapsin guiding slots of the strap fixing piece is also advantageous andeconomical from a production engineering point of view.

An advantageous improvement of the invention is to provide lateralguiding grooves on the fixing clips to attach the temple strap that islength-adjustable to the size of the wearer's head and held in a bucklewith a centerpiece to the fixing clips.

According to another characteristic of the invention, a gripping clip ismolded to the strap fixing piece that makes it even easier to put on therespirator mask because the “crown-shaped” opening of the strap is wideand folded outward at an angle, and because the wearer can use thegripping element when putting on the mask.

An embodiment of the invention is explained in greater detail below withreference to the figures. Wherein:

FIG. 1 is a representation of the head strap piece of the strap notshowing the temple and neck straps;

FIG. 2 is a view of the inside of the strap fixing piece of the headplate of the head strap piece that sits tight to the head and is made ofa synthetic material; and

FIG. 3 is a perspective view of the fixing clip for fast attachment ofthe head strap piece to the respirator mask.

FIG. 4 is a perspective view of FIG. 1.

The strap includes a one-piece head strap piece 1 made by injectionmolding from a synthetic material to which an elastic temple strap 2 anda non-stretching neck strap 3 are attached, the free ends of which canbe adjusted in length and are fastened to the mask using two fixingpoints. The head strap piece 1 consists of a head plate 4 with a strapfixing piece 5 for the temple strap 2 and the neck strap 3 and head band6 extending from the head plate 4 and split in a V shape, with fixingclips 7 molded to its two ends in which the ends of thelength-adjustable, extending neck strap are held. The free ends of theV-shaped head strap 6 are detachably connected to a fastening clip 8(see FIG. 3) that is attached to the mask.

The head strap piece 1 is thicker in the section of the head plate 4 (1mm) than in the section of the head strap 6 (0.5 mm) and is generallystiff, but when put under strain still sufficiently flexible or elasticto adjust to the shape of the wearer's head. The thinner head straps 6however are less stiff or flexible to the extent that they form an archthat approximately corresponds to the shape of the head. The wallthickness of the head strap 6 may be slightly greater towards theheat-exposed side rims or generally at their ends to ensure a longservice life under heat exposure. A head strap piece 1 designed likethat, together with the temple strap 2 attached to the strap fixing part5 and the fixing clips 7 has a crown-shaped structure and can be put onby any user without requiring extra practice or skills thanks to theeasy-sliding and smooth plastic surfaces of the head strap piece 1. Nopart of the strap can twist or tear on a wearer's hair due to friction.

The strap fixing piece 5 comprises guiding slots 9 that in generalextend horizontally and parallel to each other and are aligned in such away that the neck strap 3 they guide forms a V with the fixing points onthe mask (not shown). Two second guiding slots 10 that are in truealignment with the ends of the parallel guiding slots 9 are designed forreceiving the elastic temple strap 2. The neck strap 3 that extendsdownwards in a V shape and the generally horizontal temple strap 2 areconducted by the guiding slots 9 or 10, respectively, so that thesections of the elastic temple strap 2 on the inside of the strap fixingpiece 5 that face the wearer's head are covered by the smooth,non-elastic neck strap 3. This means that the dull and horizontalsections of the temple strap 2 are covered by the vertical slidablesections of the neck strap 3 so that the strap attachment does notcreate any resistance when a wearer puts on the respirator mask.

The ends of the temple strap 2 are attached using a buckle (not shown)that is detachably held in two lateral guiding slots 12 of therespective fixing grip in front of a transverse slot 11, and a loop (notshown) of the temple strap 2 conducted through the transverse slot 11and around the center piece of said buckle. The fixing clips 7 aremolded to the head strap 6 to extend approximately in parallel to themask wearer's temples and support the desired crown shape of the strap.

The head strap 1 is attached to the mask by means of a fixing web 17pivoted in a recess 16 of the fixing clip 7 and engaging with afastening clasp 18 of a fastening clip 8 that is connected to the mask;said fastening clasp 18 is detachably interlocked using two oppositelyspring-mounted locking clasps 15 into a disk frame eyelet 13. Afour-point strap with two-point fastening based on two fixing points(fastening clasps 18) on the mask that ensures a firm fit of the maskand easy maintenance and assembly is thus created using the fixing clips7 molded to the ends of the V-shaped head strap 6. The extending templestrap 2 that runs at the level of the wearer's temple contributesconsiderably to a safe and always gastight fit of the respirator mask,even when the wearer is exposed to physical strain or the weight of themask is increased. The good wearing properties and easy fit of the maskare due to a major extent to the flexurally stiff, easy-sliding designof the head strap piece 1 that consists of a synthetic material andwhose head straps and head plate that form the crown differ instiffness. The figure further shows that a gripping clip 14 is molded tothe lower rim of the strap fixing piece 5. The use of this gripping clipmakes it even easier to put on the respirator mask fast because theaperture angle of the strap fixing piece 5 and thus of the elastictemple strap 2 is enlarged so that the temple strap cannot twist orpinch the wearer's hair and no interfering frictional forces act uponthat hair.

The figures further show that the strap fixing piece 5 is extended atboth ends by side clips 19. These counteract any lateral torsion of thetemple strap 2 when the mask is put on. In addition, this reducesfrictional forces caused by the temple strap and shapes the strap (thetemple strap) corresponding to the shape of the head (headcircumference) when the mask is put on.

List of reference symbols 1 head strap piece 2 temple strap 3 neck strap4 head plate 5 strap fixing piece 6 head strap 7 fixing clips 8fastening clip 9 first guiding slots 10 second guiding slots 11transverse slot in 7 12 guiding groove in 7 13 disk frame eyelets 14gripping clip 15 locking clasp 16 recess in 7 17 fixing web 18 fasteningclasp of 8 19 side clips

1. A strap for full respirator masks, consisting of a head strap piecewith two head straps attached to the mask at two fixing points and acommon strap fixing piece for length-adjustable neck straps held at twoother mask fixing points, characterized in that the strap fixing piecemerges into a flexurally stiff head plate towards the head straps thatis stiffer than the head straps, and in that an extending temple strapis attached to said strap fixing piece.
 2. The strap according to claim1, characterized in that the free ends of the temple strap are attachedin a detachable and length-adjustable manner to a fixing clip connectedto each head strap to form a four-point fastening.
 3. The strapaccording to claim 1, characterized in that the head strap piece ismolded in one piece from a synthetic material with an easily slidingsurface and a greater material thickness than the head straps in thesections of the strap fixing piece, the head plate and the head strapends with fixing clips.
 4. The strap according to claim 1, characterizedin that the wall thickness of the head straps is about half the wallthickness of the head plate and the strap fixing piece.
 5. The strapaccording to claim 1, characterized in that the cross section of thehead straps increases from the outer towards the inner rim for increasedthermal resistance.
 6. The strap according to claim 2, characterized inthat the fixing clips comprise lateral guiding grooves at a transverseslot that detachably hold a fastening buckle with a center piece forfastening the temple strap and adjusting its length.
 7. The strapaccording to claim 2, characterized in that a recess closed by a pivotedfixing web is provided in the fixing clip for detachably locking thehead and temple straps to the mask at two fixing points formed byfastening clasps.
 8. The strap according to claim 1, characterized inthat the head strap piece is injection-molded in one piece from asynthetic material.
 9. The strap according to claim 1, characterized inthat first guiding slots for angular downward fastening of the neckstrap and second guiding slots for the generally horizontal fastening ofthe temple strap are provided in the strap fixing piece, wherein thefirst and second guiding slots are aligned to each other, and straps areconducted, in such a way that the smooth and non-extending neck strapcovers the dull, extending portion of the temple strap on the innersurface of the head strap piece that is facing the wearer's head. 10.The strap according to claim 1, characterized in that a gripping clip ismolded to the lower rim of the strap fixing piece.
 11. The strapaccording to claim 7, characterized in that the fastening clasp forlocking the fixing clip is provided at a fastening clip with opposingspring-mounted locking clasps, and that said fastening clip can belocked into a disk frame eyelet attached to the mask.
 12. The strapaccording to claim 1, characterized in that the strap fixing piece isextended by side clips on both ends.